How severe is CVE-2026-5538?

CVE-2026-5538 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.

Is CVE-2026-5538 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-5538?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-5538 have an EU (EUVD) identifier?

Yes. CVE-2026-5538 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19024.

When was CVE-2026-5538 published?

CVE-2026-5538 was published on 2026-04-05 and last updated on 2026-06-17.

CVE-2026-5538

CVE-2026-5538 is a medium-severity vulnerability with a CVSS 3.x base score of 6.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-918.

Key facts

Severity: Medium (CVSS 3.x base score 6.3)
CVSS v2: 6.5
CVSS v4: 5.3
EPSS exploit prediction: 0% (11th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-19024
Weakness: CWE-918
Published: 2026-04-05
Last modified: 2026-06-17

Description

A vulnerability was detected in QingdaoU OnlineJudge up to 1.6.1. Affected by this issue is the function service_url of the file JudgeServer.service_url of the component judge_server_heartbeat Endpoint. The manipulation results in server-side request forgery. It is possible to launch the attack remotely. The vendor was contacted early about this disclosure but did not respond in any way.

Frequently asked questions

What is CVE-2026-5538?: A vulnerability was detected in QingdaoU OnlineJudge up to 1.6.1. Affected by this issue is the function service_url of the file JudgeServer.service_url of the component judge_server_heartbeat Endpoint. The manipulation results in server-side request forgery. It is possible to launch the attack remotely. The vendor was contacted early about this disclosure but did not respond in any way.
How severe is CVE-2026-5538?: CVE-2026-5538 has a CVSS 3.x base score of 6.3, rated medium severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability low.
Is CVE-2026-5538 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (11th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-5538?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-5538 have an EU (EUVD) identifier?: Yes. CVE-2026-5538 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-19024.
When was CVE-2026-5538 published?: CVE-2026-5538 was published on 2026-04-05 and last updated on 2026-06-17.

References

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